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Propagation characteristics of reverse combustion significantly impact the conversion of solid fuels in packed beds, especially under variable reaction atmosphere conditions. In this study, the propagation of reverse combustion was experimentally studied in an oxygen-limited and -enriched O 2 /N 2 flow with an oxygen concentration range of 21–100 % for a bed packed with rice husk. The temperature profile measured by thermocouples along the bed height was processed to appreciate the driving mechanism of combustion front, as well as the reaction structure inside the bed. Besides, the contribution of volatiles gas-phase oxidation and char surface oxidation to reverse combustion was also evaluated. Results show that compared to the air case, an oxygen-enriched condition broadens the operating range of oxygen flow rate for the oxygen-limited reverse combustion. Under high oxygen concentration conditions, the low-temperature oxidation of rice husk inside the reaction front becomes enhanced. Such chemical reaction effect widens the whole reaction front thickness and thereby reduces the oxidation intensity in local regions, resulting in a faster ignition rate and a lower temperature for combustion front. It is found that this process is dominated by the gas-phase oxidation of volatiles, of which oxygen consumed is above 60 % of the supplied. As oxygen concentration increases, the gas-phase oxidation of volatiles becomes further enhanced. Correspondingly, the oxidation ratio of char is gradually approaching a limit, about 12 %, especially at the oxygen concentration above 50 %. These findings will facilitate a better fundamental understanding of driving mechanism of this special combustion process and thereby provide an important theoretical basis for efficient thermal conversion of solid fuels. [ABSTRACT FROM AUTHOR]

Nephrolithiasis is a systemic metabolic disease with a worldwide incidence that is increasing yearly, as well as a high recurrence rate; however, this disease's pathogenesis has not been thoroughly elucidated to date. Several epidemiological studies have shown that the risk for developing kidney stones increases in people with dyslipidemia. To explore the mechanism of lipid-induced kidney stones, we established a mouse model for renal urolithiasis based on intraperitoneal injections of glyoxylate (120 mg/kg/d). Lipidomics based on ultra high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-QTOF-MS/MS) was performed to determine the changes in lipid metabolism in serum and kidneys. We screened 179 and 196 different lipid metabolites in the kidneys and serum, respectively, including fatty acyls, glycerophospholipids, sphingolipids, glycerolipids and prenol lipids. We found that polyunsaturated fatty acids, such as arachidonic acid, eicosapentaenoic acid, and docosahexoenoic acid, and ceramides and lysophosphocholines mediated inflammatory responses and that the oxidative stress induced by oleylethanolamine and glycerophosphoethanolamine plasmalogens is closely related to the development of kidney stones. These results provide strong evidence for the relationship between lipid metabolism and the development of kidney stones and suggest a clear direction for future research. [ABSTRACT FROM AUTHOR]

Indiscriminate drug administration may lead to drug therapy results with varying effects on patients, and the proposal of personalized medication can help patients to receive effective drug therapy. Conventional ways of personalized medication, such as pharmacogenomics and therapeutic drug monitoring (TDM), can only be implemented from a single perspective. The development of pharmacometabolomics provides a research method for the realization of precise drug administration, which integrates the environmental and genetic factors, and applies metabolomics technology to study how to predict different drug therapeutic responses of organisms based on baseline metabolic levels. The published research on pharmacometabolomics has achieved satisfactory results in predicting the pharmacokinetics, pharmacodynamics, and the discovery of biomarkers of drugs. Among them, the pharmacokinetics related to pharmacometabolomics are used to explore individual variability in drug metabolism from the level of metabolism of the drugs in vivo and the level of endogenous metabolite changes. By searching for relevant literature with the keyword "pharmacometabolomics" on the two major literature retrieval websites, PubMed and Web of Science, from 2006 to 2023, we reviewed articles in the field of pharmacometabolomics that incorporated pharmacokinetics into their research. This review explains the therapeutic effects of drugs on the body from the perspective of endogenous metabolites and pharmacokinetic principles, and reports the latest advances in pharmacometabolomics related to pharmacokinetics to provide research ideas and methods for advancing the implementation of personalized medication. [ABSTRACT FROM AUTHOR]

Gradation and quality utilization of low-rank coal is promising. In this study, a special counter-current combustion process, characterized by a combustion front traversing the bed against the air supply direction, was innovatively proposed to achieve the carbonization and activation of low-rank coal. This combustion process was first analysed experimentally in a fixed bed test rig. At an air equivalence ratio as low as 0.25, this combustion process was of a front temperature of 889 °C and self-sustainedly traversed the fuel bed at a propagating rate of 0.33 m/h. Accompanied by its propagation, about 82.5% of volatile matter inside the coal was removed. Due to different reaction phases inside the bed, the solids were in-situ activated by self-produced active components. Based on this, intensification experiments of carbonization and activation were carried out in a moving bed test rig. By moving the bed, the heat transfer near the combustion front tended to a quasi-equilibrium state and the residence time of the solids in the high temperature zone was greatly prolonged. The carbonization and activation effects on the solids were promoted. The carbonization effect almost approached the limit because the removal ratio of volatile matter inside the coal was as high as 98.4%. When external heating and active substances intervened, activation reactions of the solids (namely, C–H 2 O and C–CO 2) were intensified in the char reaction phase. The specific surface area and pore volume of the activated char increased up to 594 m2/g and 0.371 cm3/g. Correspondingly, its adsorption values of iodine and methylene blue were 732 and 76 mg/g. This work provides a technical solution for the in-situ high-quality utilization of low-rank coal. • A method to carbonize and activate coal by a combustion process is proposed. • Dynamically propagating combustion front removes 98.4% of volatile matter. • Activation of solids is related to bed structure with different conversion zones. • Intervention of auxiliary heating and active substances promotes the activation. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Orthosiphon stamineus (OS), a traditional Chinese herb, is often used for promoting urination and treating nephrolithiasis. Aim of the study Urolithiasis is a major worldwide public health burden due to its high incidence of recurrence and damage to renal function. However, the etiology for urolithiasis is not well understood. Metabonomics, the systematic study of small molecule metabolites present in biological samples, has become a valid and powerful tool for understanding disease phenotypes. In this study, a urinary metabolic profiling analysis was performed in a mouse model of renal calcium oxalate crystal deposition to identify potential biomarkers for crystal-induced renal damage and the anti-crystal mechanism of OS. Materials and methods Thirty six mice were randomly divided into six groups including Saline, Crystal, Cystone and OS at dosages of 0.5 g/kg, 1 g/kg, and 2 g/kg. A metabonomics approach using ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) was developed to perform the urinary metabolic profiling analysis. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were utilized to identify differences between the metabolic profiles of mice in the saline control group and crystal group. Results Using partial least squares-discriminant analysis, 30 metabolites were identified as potential biomarkers of crystal-induced renal damage. Most of them were primarily involved in amino acid metabolism, taurine and hypotaurine metabolism, purine metabolism, and the citrate cycle (TCA). After the treatment with OS, the levels of 20 biomarkers had returned to the levels of the control samples. Conclusions Our results suggest that OS has a protective effect for mice with crystal-induced kidney injury via the regulation of multiple metabolic pathways primarily involving amino acid, energy and choline metabolism. [ABSTRACT FROM AUTHOR]

A representative congener of polybrominated diphenyl ethers in the environment, 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47), is associated with male reproductive toxicity, yet the underlying mechanisms remain largely unclear. In this study, mice were administered environmentally relevant concentrations of BDE-47 for six weeks. Histopathological observations showed that BDE-47 induced inflammatory reactions and damaged the testes. By conducting an integrated proteomic and metabolomic analysis coupled with a bioinformatic analysis using ingenuity pathway analysis (IPA) methods, we found that BDE-47 mainly affected the molecules involved in free radical scavenging, cell death and survival, neurological disease, and inflammatory response. IPA canonical pathways showed inflammatory and apoptosis pathways, including hepatic fibrosis/hepatic stellate cell activation, the GP6 signaling pathway, tight junction signaling, acute phase response signaling, LXR/RXR activation, unfolded protein response, and FXR/RXR activation, which are related to male reproductive toxicity. Key transcriptional regulator networks were activated via a focus on upstream regulator analysis. The expression of MYC and Clu as the core transcriptional factor and targeted protein, respectively, was verified. It is further proposed that MYC may contribute to the etiology of male reproductive toxicity. These findings will improve our understanding of the mechanisms responsible for BDE-47-induced male reproductive toxicity, which may promote the discovery of useful biomarkers indicative of BDE-47 exposure. [ABSTRACT FROM AUTHOR]

Major depressive disorder (MDD) and bipolar disorder (BD) are psychiatric disorders with overlapping symptoms, leading to high rates of misdiagnosis due to the lack of biomarkers for differentiation. This study aimed to identify metabolic biomarkers in urine samples for diagnosing MDD and BD, as well as to establish unbiased differential diagnostic models. We utilized a metabolomics approach employing ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) to analyze the metabolic profiles of urine samples from individuals with MDD (n = 50), BD (n = 12), and healthy controls (n = 50). The identification of urine metabolites was verified using MS data analysis tools and online metabolite databases. Two diagnostic panels consisting of a combination of metabolites and clinical indicators were identified—one for MDD and another for BD. The discriminative capacity of these panels was assessed using the area under the receiver operating characteristic (ROC) curve, yielding an area under the curve (AUC) of 0.9084 for MDD and an AUC value of 0.9017 for BD. High-resolution mass spectrometry-based assays show promise in identifying urinary biomarkers for depressive disorders. The combination of urine metabolites and clinical indicators is effective in differentiating healthy controls from individuals with MDD and BD. The metabolic pathway indicating oxidative stress is seen to significantly contribute to depressive disorders. • Accurate identification of differential metabolites between healthy controls and disease groups using UHPLC-MS and multiple databases. • Models utilizing urinary metabolites combined with clinical indicators are reliable for the diagnosis of MDD and BD. • Diagnostic models emphasize the important role of oxidative stress in the pathogenesis of psychiatric disorders. [ABSTRACT FROM AUTHOR]

Objective: Alzheimer's disease (AD) is characterized by the progressive degeneration and damage of neurons in the brain. However, developing an accurate diagnostic assay using blood samples remains a challenge in clinic practice. The aim of this study was to explore senescence‐associated secretory phenotypes (SASPs) in peripheral blood using mass spectrometry based multi‐omics approach and to establish diagnostic assays for AD. Methods: This retrospective study included 88 participants, consisting of 29 AD patients and 59 cognitively normal (CN) individuals. Plasma and serum samples were examined using high‐resolution mass spectrometry to identify proteomic and metabolomic profiles. Receiver operating characteristic (ROC) analysis was employed to screen biomarkers with diagnostic potential. K‐nearest neighbors (KNN) algorithm was utilized to construct a multi‐dimensional model for distinguishing AD from CN. Results: Proteomics analysis revealed upregulation of five plasma proteins in AD, including RNA helicase aquarius (AQR), zinc finger protein 587B (ZNF587B), C‐reactive protein (CRP), fibronectin (FN1), and serum amyloid A‐1 protein (SAA1), indicating their potential for AD classification. Interestingly, KNN‐based three‐dimensional model, comprising AQR, ZNF587B, and CRP, demonstrated its high accuracy in AD recognition, with evaluation possibilities of 0.941, 1.000, and 1.000 for the training, testing, and validation datasets, respectively. Besides, metabolomics analysis suggested elevated levels of serum phenylacetylglutamine (PAGIn) in AD. Interpretation: The multi‐omics outcomes highlighted the significance of the SASPs, specifically AQR, ZNF587B, CRP, and PAGIn, in terms of their potential for diagnosing AD and suggested neuronal aging‐associated pathophysiology. [ABSTRACT FROM AUTHOR]

Few studies have examined the relationship between lipid metabolism and kidney stone formation, particularly the role of key lipid regulatory factors in kidney stone formation. We evaluated the effect of the lipid regulatory factor‐peroxisome proliferator‐activated receptor alpha on the formation of renal stones in mice by injecting them with glyoxylate followed by treatment with either a peroxisome proliferator‐activated receptor alpha agonist fenofibrate or an antagonist GW6471 (GW). Liquid chromatography coupled with trapped ion mobility spectrometry‐quadrupole‐time‐of‐flight mass spectrometry‐based lipidomics was used to determine the lipid profile in the mouse kidneys. Histological and biochemical analyses showed that the mice injected with glyoxylate exhibited crystal precipitation and renal dysfunction. Crystallization decreased significantly in the fenofibrate group, whereas it increased significantly in the GW group. A total of 184 lipids, including fatty acyls, glycerolipids, glycerophospholipids, and sphingolipids differed significantly between the mice in the model and control groups. Peroxisome proliferator‐activated receptor alpha activity negatively correlated with glyoxylate‐induced kidney stone formation in mice, which may be related to improved fatty acid oxidation, maintenance of ceramide/complex sphingolipids cycle balance, and alleviation of disorder in phospholipid metabolism. [ABSTRACT FROM AUTHOR]

Background: Flavonoids with various structures play a vital role in plant acclimatization to varying environments as well as in plant growth, development, and reproduction. Exogenous applications of ethylene and 1-aminocyclopropane carboxylic acid (ACC), could affect the accumulation of flavonoids. Very few attempts have been made to investigate the effect of 1-aminocyclopropane carboxylic acid oxidase (ACO), a unique enzyme that catalyzes ACC to ethylene, on genes and metabolites in the flavonoid biosynthetic pathway. In this study, two ACOs in safflower (CtACOs) were cloned, and then transgenic safflower with overexpressed CtACO1 was generated through the Agrobacterium-mediated floral dipping method. Results: CtACO1 and CtACO2 were both characterized by the 2-oxoglutarate binding domain RxS and the ferrous iron binding site HxDxnH as ACOs from other plants. However, the transcript levels of CtACO1 in flowers at stages I, II, III, and IV were all higher than those of CtACO2. At the cellular level, by using electroporation transformation, CtACO1 was found to be localized at the cytomembrane in onion epidermal cells. CtACO1 overexpression had varying effects on genes involved in the ethylene and flavonoid biosynthetic pathways. The metabolites analysis showed that CtACO1 overexpression lines had a higher accumulation of quercetin and its glycosylated derivatives (quercetin 3-β-d-glucoside and rutin). In contrast, the accumulation of quinochalcones (hydroxysafflor yellow A and carthamin), kaempferol glycosylated derivatives (kaempferol-3-O-β-rutinoside and kaempferol-3-O-β-d-glucoside), apigenin, and luteolin in CtACO1 overexpression lines were decreased. Conclusion: This study confirmed the feasibility of applying the floral dipping method to safflower and showed a novel regulatory effect of CtACO1 in the flavonoid biosynthetic pathway. It provides hypothetical and practical groundwork for further research on regulating the overall metabolic flux of flavonoids in safflower, particularly hydroxysafflor yellow A and other quinochalcones, by using appropriate genetic engineering strategies. [ABSTRACT FROM AUTHOR]

• Development of a sensitive and reliable LC-MS/MS method for the accurate quantification of six α-hydroxyl ceramides in serum. • Strong support for the research of biological function of α-hydroxyl ceramides in the future. • Revealing the α-hydroxyl ceramides associated with sepsis. Alpha-hydroxy ceramides are not only the precursors of many complex sphingolipids, also play a major role in membrane homeostasis and cellular signal transduction. However, current research rarely involved quantitative methods for α-hydroxy ceramides, which greatly restricts the study of its biological function. This work aimed to develop a reliable assay for the accurate quantification of α-hydroxy ceramides in vivo study. LC-MS/MS method was developed for the accurate quantification of six α-hydroxy ceramides of Cer(d18:1/16:0(2OH)), Cer(d18:1/18:0(2OH)), Cer(d18:1/18:1(2OH)), Cer(d18:1/20:0(2OH)), Cer(d18:1/22:0(2OH)) and Cer(d18:1/24:1(2OH)) in mice serum. This assay was validated with low limit of quantitation of 3.125 ng/mL, a dynamic range of 3.125–400 ng/mL (R2 > 0.99), precision (<15 %), and accuracy (88 % to 115 %). Applying the method to the determination of α-hydroxy ceramides in the serum of sepsis mice, the levels of Cer(d18:1/16:0(2OH)), Cer(d18:1/20:0(2OH)), Cer(d18:1/24:1(2OH)) were significantly elevated in LPS-induced septic as compared to the normal control. In conclusion, this LC-MS method was qualified in α-hydroxy ceramides quantification in vivo and a significant association was found between α-hydroxy ceramides and sepsis. [ABSTRACT FROM AUTHOR]

Veratrum nigrum L. (VN) is a poisonous traditional Chinese medicine herb present since thousands of years in China. Clinical studies have shown that VN has the ability to cause hepatotoxicity, which severely limits its clinical use. The mechanism of its hepatotoxicity has not been fully elucidated. The purpose of this study was to develop and characterize a model of acute and chronic hepatotoxicity induced by Veratrum nigrum L. extract (VNE) to understand the mechanism of liver tissue metabolomics approach using on ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOFMS). Mice were administered with VNE in the acute and chronic phases. Histopathologic inspections and biochemistry analysis disclosed severe liver damage after exposure to VNE. A partial least-squares discriminant analysis (PLS-DA) of the metabolomic profiles of rat liver tissues highlighted a number of metabolic disturbances induced by VNE, focusing on purine and pyrimidine metabolism, tryptophan metabolism, phospholipid metabolism, sphingolipid metabolism and fatty acid metabolism. These findings could well explain VNE-induced acute and chronic hepatotoxicity and reveal several potential biomarkers associated with this toxicity. This indicates that UHPLC-Q-TOFMS-based metabolomics approach demonstrated its feasibility and allowed a better understanding of VNE-induced liver toxicity dynamically. [ABSTRACT FROM AUTHOR]

The herbal pair Zhimu-Baihe (Zhimu: Anemarrhena asphodeloides ; Baihe: Lilium brownii var. viridulum ) is a traditional Chinese medicament used for the treatment of depression. However, the relevant mechanisms of action has not been clarified. This study investigated the anti-depressant activity of the total saponins from Zhimu and Baihe and the mechanisms underlying using a chronic unpredictable mild stress (CUMS)-induced rat model of depression. High performance liquid chromatography with electrochemical detection (HPLC-ECD) was applied to determine the levels of three monoamine neurotransmitters, 5-hydroxytryptamine (5-HT), noradrenaline (NE) and dopamine (DA), in the rat hippocampus. Optimized pretreatment of samples and mass spectrometry conditions were used to analyse the metabonomic profile of the hippocampus. The 5-HT and NE levels in the CUMS group were reduced compared with the control group, whereas all groups had similar DA levels. The metabonomic profile of the hippocampus revealed 32 differential metabolites between the CUMS and control group, among which 18 metabolites were significantly recovered in the Anemarrhena saponins and Lilium saponins (AL) combination intervention group. These results suggested an anti-depressant effect of AL. Moreover, 24 metabolites in AL group were better recovered compared with the Anemarrhena saponins (AS) or Lilium saponins (LS) intervention groups, suggesting a synergetic effect of AS and LS in the treatment of depression. The anti-depressant effect might be related to the regulation of several metabolic pathways, including monoamine neurotransmitter synthesis (especially 5-HT and NE), and amino acid, fatty acid, and phospholipid metabolism in rats. [ABSTRACT FROM AUTHOR]

• SA-AKI was effectively alleviated with RCE treatment. • 25 differential metabolites related to the pathological processes of SA-AKI and the effects of RCE were identified. • A compound-metabolite-target-disease network was constructed to explore the mechanisms of RCE against SA-AKI. • RCE may mitigate SA-AKI through regulating these 17 overlapping target proteins in the network. Sepsis remains the most common cause of acute kidney injury (AKI) in critically ill patients, increasing the risk of in-hospital and long-term death. Rhizoma Coptidis (RC), a classical traditional Chinese herb, exhibits anti-inflammatory and antioxidant properties in various diseases including sepsis. This study aimed to investigate the protective effects of RC extracts (RCE) against sepsis-associated acute kidney injury (SA-AKI) and explore the underlying mechanisms with metabolomics-based network pharmacology. The results showed that RCE improved renal function and histological injury and decreased reactive oxygen species (ROS) production in SA-AKI. Using ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF/MS), 25 differential metabolites were identified that had a close connection with the pathological processes of SA-AKI and the effects of RCE. Afterward, a compound-metabolite-target-disease network was constructed and 17 overlapping target proteins of the components of RCE, the differential metabolites, and the disease-related genes were discovered. Among these overlapping target proteins, RCE increased the nuclear translocation of nuclear factor-erythroid 2-related factor-2 (Nrf2), the protein expression of heme oxygenase-1 (HO-1), the mRNA expression of peroxisome proliferator activated receptor α (PPARα) and reduced nitric oxide synthase 2 (NOS2) activity. In addition, molecular docking revealed that both berberine and quercetin could bond with NOS2 and PPARα, respectively. Therefore, RCE demonstrated protective effects for SA-AKI through the regulation of metabolism and different signaling pathways. [ABSTRACT FROM AUTHOR]

Sepsis, in addition to causing fatality, is an independent risk factor for cognitive impairment among sepsis survivors. The pathologic mechanism of endotoxemia induced acute neuro-inflammation still has not been fully understood. For the first time, we found the disruption of neurotransmitters 5-HT, impaired neurogenesis and activation of astrocytes coupled with concomitant neuro-inflammation were the potential pathogenesis of endotoxemia induced acute neuro-inflammation in sepsis survivors. In addition, dioscin a natural steroidal saponin isolated from Chinese medicinal herbs, enhanced the serotonergic system and produced anti-depressant effect by enhancing 5-HT levels in hippocampus. What is more, this finding was verified by metabolic analyses of hippocampus, indicating 5-HT related metabolic pathway was involved in the pathogenesis of endotoxemia induced acute neuro-inflammation. Moreover, neuro-inflammation and neurogenesis within hippocampus were indexed using quantitative immunofluorescence analysis of GFAP DCX and Ki67, as well as real-time RT-PCR analysis of some gene expression levels in hippocampus. Our in vivo and in vitro studies show dioscin protects hippocampus from endotoxemia induced cascade neuro-inflammation through neurotransmitter 5-HT and HMGB-1/TLR4 signaling pathway, which accounts for the dioscin therapeutic effect in behavioral tests. Therefore, the current findings suggest that dioscin could be a potential approach for the therapy of endotoxemia induced acute neuro-inflammation. [ABSTRACT FROM AUTHOR]